The present invention relates to so-called insulating-glass units or panes which can be used as shatter-, bullet- and/or sound-proof barriers and/or as thermally insulating light-transmitting inserts in windows, doors or the like. More particularly, the invention relates to improvements in laminates of the type disclosed in my U.S. Pat. No. 4,299,639. Still more particularly, the invention relates to improvements in spacer frames of the type disclosed in the commonly owned copending patent application Ser. No. 598,444 filed Aug. 9, 1984 for "Method of and apparatus for making spacers for use in multiple-pane windows or the like". Reference may also be had to DE-OS 30 32 825.
Spacer frames are normally made from extruded hollow aluminum profiles which are filled with a flowable pulverulent or granular desiccant and are bent into the form of or otherwise assembled into rectangles or otherwise configurated circumferentially complete bodies for insertion between the marginal portions of two overlapping light-transmitting plates. Such spacer frames are or can be formed with one or more openings for admission or evacuation of a gaseous fluid. The opening or openings are provided in that wall or those walls of the frame which extend between and are not immediately adjacent to the plates. The opening or openings are tightly sealed when the installation of the frame between two spaced-apart parallel light-transmitting plates is completed or is about to be completed.
One or more openings are normally provided (as a rule by drilling) into the frame of an insulating-glass pane or unit wherein the space which is surrounded by the spacer frame-is to be filled with a gaseous fluid other than air. The gas which is to ultimately fill the space within the confines (not in the interior) of the spacer frame is admitted by way of a first opening, and such gas expels air by way of a second opening. The first opening is normally located at a level below the second (air evacuating) opening. Once the space within the frame is filled with the selected gaseous fluid, the two openings are sealed to prevent the flow of air, steam and/or any other fluid media therethrough. In many instances, the openings are sealed by a compound which is admitted between the marginal portions of the light-transmitting plates and surrounds the spacer frame. In other words, the openings are sealed from the atmosphere by a compound which surrounds the outer wall of the tubular body of the frame and not by bungs, plugs, corks or otherwise configurated male sealing members extending into the openings. The absence of such positive sealing is likely to result in leakage of gases into and from the interior of the spacer frame. If a plug is used, it normally extends well beyond the outer side of the spacer frame so that it is visible in the fully assembled laminated pane to detract from its appearance. Moreover, heretofore known and used sealing devices (including plugs and sealing compounds) cannot ensure reliable sealing of the openings for extended periods of time (particularly for several years) so that the space within the confines of the spacer frame is likely to receive moisture which condenses and fogs the light-transmitting plates.
Another drawback of heretofore known spacer frames with openings for admission of gaseous fluids into and for evacuation of gaseous fluids from the spaces within the confines of such frames is that the frames cannot be filled with a desiccant because the desiccant (or a high percentage of desiccant) would be expelled during expulsion of air from the space within the confines of the frame. The desiccant would also tend to flow from the internal space of the frame into the space within the confines of the frame to detract from the appearance of the finished insulating-glass units.
Another reason for the making of holes (normally a single hole) in the spacer frame of an insulating-glass plate is to allow for long-lasting utilization of the insulating-glass unit at locations well above the sea level, even if the unit was manufactured in a plant much closer to the sea level. In such instances, the single opening is connected with a pressure equalizing or balancing device which ensures that the pressure differential (if any) between the space within the confines of the frame and the surrounding atmosphere will not deviate from a desirable range. The problems which are encountered due to the provision of a single hole for pressure balancing purposes are the same as the aforediscussed problems in connection with the holes or openings which are made for the purpose of admitting a selected gaseous fluid into and for expelling air from the space within the confines of the frame, i.e., the internal space of the frame and/or the space within the confines of the frame is not likely to be adequately sealed from the surrounding atmosphere and/or the seals which are used for the hole or holes are likely to detract from the appearance of the insulating-glass unit. Moreover, the internal space of the frame cannot be filled with a desiccant.